Rapper Chief Keef Arrested For Doing 110mph In A 55mph Zone

17-year-old Chief Keef was caught ON TAPE shattering the speed limit in Illinois this week — allegedly doing 110mph in a 55mph zone — and TMZ has dash cam footage of the subsequent police chase … and arrest.

The video starts out pretty tame — until out of nowhere, Keef barrels past the idling police cruiser in his BMW X6 M … and the cops peel out after him. It takes roughly two minutes for officers to catch up to Keef and pull him over.

As we reported, Keef was eventually arrested for speeding and having too many people in his car (he only has a driving permit). The arrest is also on tape.

But the best part — wait ’til you hear the arresting officer’s voice when he finds out Keef’s got $8,000 CASH in his pocket …